In brief (with the proviso that IamNotaLawyer), fair use allows excerpts of a CopyRighted work to be used for teaching, "scholarship", news reporting, and criticism.

Posting an entire copyrighted work without the copyright holder's permission violates fair use. Please don't do this on Wiki. -- DaveSmith

But isn't this all changed now with the DMCA? CopyRight now is superseded by ParaCopyRight?, you can not get an excerpt if it requires circumventing a TechnicalProtectionMeasure? -- AndrewMcMeikan

No, not really. DMCA attempts to create a lockable software container whereupon it would be clear (in a legal sense) when a user transgressed across it (otherwise software-on-disk is just "code exposed to the public domain"), but this is mostly a societal agreement which won't necessarily hold sway over time. The reason is thus: there is no legal right to profit. If software makers want to make revenue, exclusively, for their software, they can set up a business where people can come in and use the software on their own (protected) machines where the machine code can't be accessed.

That being said, those who figured out the code for DMCA should be noted as doing a service for the underdog, but keep their achievement on the "downlow", so it can continue to be a service to humanity.

Copyright is about protecting "authorship", or, in other words, preserving FairCreditAssignment. (I.e. you can't use another's words under your own name.)

Fair-use allows others to use another's work, possibly making a derived work. Acknowledging that after publication, it is easy to copy text or machine code (in whole or in part), "Fair Use" says you cannot do so simply for personal gain if you are depriving the original author of legitimate gains. If copyright by an individual, non-commercial re-use is always allowed. The only known points of contention are with corporate claims.

Points to evaluate:

If you are enhancing the intellectual or creative community by reusing already published material, you are likely *protected*. (ShareAlike)

No, you are not likely to be protected. The law does not make exceptions for some notion of community enhancement.

If you make money from another's material, you are not protected and claims could be held against you (though they may not win, depending on whether the "spirit" of your use was innocent and/or fair)

{In the UK, not making money off the material does not grant immunity from prosecution}.

Nor should it.

If you are re-using, non-commercially, of an individual's copyright, you are protected, but are probably not if it is a corporate copyright

{Vague to the point of meaninglessness}.

And untrue. If you're "re-using an individual's copyright" -- which I take to mean stealing someone's intellectual property -- the law does not distinguish individuals from corporations. You are only "protected" by the fact that individuals often lack the resources to take you to court.

...using an individual's copyright -- "which I take to mean stealing someone's intellectual property": You are an idiot. Please delete your nonsense.

Rather than cast aspersions, wouldn't it be more effective to rationally identify precisely how I am being "an idiot"?

The WikiPedia is wrong, and it even says so. WikiPedia isn't always authoritative, but generally only a representation of "mass consensus", however misguided. I'm only saying what's defendable, not what the level of the law has created.

Be that as it may, the description of fair use above is simplistic to the point of being misleading. I'd encourage you to remove or correct it, rather than spread misinformation.

You're speaking as if the law exist for its own sake: it doesn't. The law exists to serve People, not lawyers.

What you want the law to be has nothing to do with what the law is.

What the law "is", is not always relevant to what would be decided, should someone make the sound and correct arguments, in court. This is called CaseLaw.

CaseLaw is generally not the result of sound and correct arguments, merely the result of finding a judge or jury who will wave your argument through on some basis, sound or otherwise. Entropy ensures that bad CaseLaw generally outweighs the good as it is easier to find a stupid judge than an intelligent one and therefore easier for a good law to be undermined by bad CaseLaw than for a bad law to be fixed by good CaseLaw.